Submerged Turret Production

The Submerged Turret Production (STP) is a unique, innovative and flexible turret mooring system for Floating Production, Storage and Offloading vessels (FPSO) making it suitable for a wide range of applications. As a further development of the STL system, STP is combined with a high pressure multi-path swivel to create a complete turret and swivel package.

STP or FPSO mooring is developed from the basis of the proven STL system. The STP swivel mounted on top of the turret buoy transfers oil, water, gas, signals and power from the geo-stationary riser system to the piping and cabling system of the freely weather-vaning production vessel.

As for STL, the STP system allows for schedule decoupling between the offshore and the shipyard work. The disconnect feature of the buoy simplifies unplanned repair, upgrading, inspections and replacement of the FSO, as well as abandonment of the field.

Permanent or Disconnect Mooring

As for STL, the STP system can be designed for disconnect service or for permanent mooring throughout the field life.

STP Integration

The STP compartment in the FPSO is a cylinder extending from bottom to upper deck with the receiving cone as the lower part. With a diameter of 10 to 18 meters, the impact on the hull is minimal. Only local reinforcements of standard steelwork are required. The turret integration into the FPSO is simplified by bearing structures integrated in the STP buoy as opposed to bearings integrated with FPSO hull.

STP System References

STP systems in service cover a wide range of application from harsh North Sea environment to cyclone prone areas such as China or Australia, mooring caters for sea as high as 16 m Hs (Significant Wave Height), water depth up to 2600 m, vessel sizes up to VLCCs, through-put up to 600,000 BOPD.etc.

STP in Ice

Icebergs and ice ridges in arctic environments are better addressed with the quick disconnect features provided by the STP system. STP systems are verified in ice environments and model tests have documented survival of a vessel moored in 1.6 m level ice with drift speed of 0.75 m/s.